I have seen a few cases where people had refund issues and there was an agent involved which made everything more complicated.
This is just the latest example :
Hi All, We were traveling via Lufthansa (booked through MyTrip) from Dublin Airport in July 2024 and our flight was canceled by Lufthansa due to climate activists sitting on the runway of Frankfurt Airport. The Lufthansa told us to look at alternatives ourselves as they couldn't accommodate us...
www.askaboutmoney.com
I don't know who mytrip is, but why would anyone book through them and not directly with the airline?
I have a bit of insight into this business having worked at many OTAs and airlines (including in direct succession an OTA and then a very well-known Irish Airline who for many years have been in legal and verbal battles with each other). In short my advice is, as a general rule book directly with the airline, but you can get great mileage (yes, that's a pun) doing your research with OTAs such as skyscanner for routes you are unfamiliar with. Hotels are a different matter which I will come back to.
OTAs have the great advantage of showing you all the options from different airlines, including creative routings. But OTAs have to make a profit and how do they do that? Well first, consider there are broadly speaking two categories of airlines - the airlines that sell through aggregators such as Amadeus, and those that don't. The former are typically the old "flag carriers" (an old term but it's a useful one for these purposes), and the latter are typically the "low cost airlines" which traditionally sell direct to customer only. With an OTA, you are on much safer ground booking a "flag carrier" because they have contracts with the aggregators and everything is "above board". Also they have very complex pricing models and you might get discounts compared with the airline's own website. With a low cost airline, not so. They may have contracts with the OTA or one of the aggregators, but they may not - and as a consumer, how would you know? The OTAs access flight data from low cost airlines in a number of ways, sometimes directly through online APIs provided by the airline (this is "above board" and they would have a contract), sometimes though aggregator services like Travelocity which access the airline's APIs, or other times through screen-scraping done by the OTA themselves or by a aggregator - this latter is NOT above board and this can get you into a whole heap of trouble down the line if they airline chooses to make things difficult for you or you need to claim refunds, change flights, change passenger data, etc. And how do the OTAs make money? Well in all the "contractual" arrangements, they get a commission from the flight price, so that's above board and you shouldn't be paying more. But in the "non contractual" arrangments they may well add on extras like service fees - one of the tricks is to show a discount on the airline flight price, but then more than make it back in a hefty service fee. And in general, everyone in the industry is trying to sell you extras, car booking to take just one example, this is called "ancillary revenue" in the trade. Personally I avoid all the ancillary services offered unless they are intrinsic to the core service, e.g. bag allowance or seat allocation, so I mean, avoid the car hire, ground transportation, insurance - I am skeptical you would get the best deal on these from the airline or OTA, although I guess it could happen.
What about hotels? In my experience hotels are always in contractual arrangements with the OTAs, booking.com, hotels.com etc. We don't meet this screen-scraping issue. The contracts usually involves a commitment that the hotels don't undercut the OTA on their own "direct to customer" websites. So you should be fine booking hotels through OTAs, but I would stick with the better known OTAs, not whoever happens to appear in your google search results. Some major accommodation OTAs such as the ones I mentioned above have their own loyalty programs so you can save money if you use them regularly. And remember, you can always phone up the hotel and try to get a better rate than they list on their website. It sometimes works (when they sell through an OTA the OTA takes a very large whack as commission, so the hotel has this to play with, if they choose.)
Update: I omitted to mention that the OTAs are very good at marketing, so in some countries their brand awareness is very high. They also appear at the top of your google searches. This is the main reason people use them!